A New Cellulose-Based Fluorescent Probe for Specific and Sensitive Detection of Cu2+ and Its Applications in the Analysis of Environmental Water

Abstract

In this work, a novel fluorescent probe CMC−GE−AQ with an effective sensitive detection ability for Cu2+ was synthesized and constructed by using carboxymethyl cellulose (CMC) as the skeleton and 8-aminoquinoline (AQ) as the fluorophore. This probe exhibited a highly specific “turn-off” fluorescence response to Cu2+, and the fluorescence color changed from bright orange to colorless after adding Cu2+. The probe could selectively detect Cu2+ in a complex environment and its detection limit (LOD), the binding constant (Ka) and the numbers of binding sites (n) were calculated to be 6.4 × 10−8 mol L−1, 1.7 × 106 mol−1 L and 1.2, respectively. The sensing detection mechanism was confirmed by X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations. In addition, the probe CMC−GE−AQ was successfully applied to detect Cu2+ in real water samples, and CMC−GE−AQ-based fluorescent microspheres can serve as a convenient tool for the detection of Cu2+.